Investors looking to play the crippling drought that has sent corn prices soaring should look to companies that develop fertilizers, said Malcolm Gissen, co-manager of the Encompass Fund and President of Malcolm Gissen and Associates.

Corn prices have shot up 60 percent since the drought started earlier this summer, decimating crop yields.

Farmers, meanwhile, will do everything possible to produce what they can and that includes buying more fertilizer and other industrial products to produce as many crops as possible.

"We believe there will be greater use of fertilizer and so if you look at companies like Potash (POT) or Agrium (AGU), those are companies that should do well because farmers should be using a lot more fertilizers to increase their production.”

The U.S. Agriculture Department has cut its forecast for this year's corn and soybean output two times because of the drought.

The USDA forecast the nation's biggest harvest ever in the spring, when farmers planted 96.4 million acres of corn — the most since 1937, according to The Associated Press.

Meanwhile, investors shouldn't look past oil companies either.

Prices have been rising due to maintenance issues on North Sea oil rigs as well as due to ongoing tensions between Israel and Iran.

Fears that a standoff between Iran and the West and Israel over Tehran's nuclear ambitions sent oil soaring earlier this year on fears Iran would close the Strait of Hormuz, a narrow waterway connecting oil-rich Persian Gulf countries with the rest of the world.

Iran agreed to talks, which sent prices falling, but saber-rattling has been building anew.

"Oil is due for continued gains. The companies that are producing oil are doing extremely well. I’m talking mostly about the larger companies. So we’ve seen Chevron and Exxon, for example, reaching 52-week highs. That is likely to continue because, at these prices, these companies are very profitable," Gissen said.

Smaller companies haven't done as well but investors should look at that segment closely.

"There is real opportunity in that sector," Gissen said.

"Magnum Hunter is a company out of Houston, MHR is the symbol. They were producing 10,000 barrels of oil equivalent a day at the beginning of 2011. They’re now producing about 20,000. So they’ve doubled their production in a year and a half and we think they will be very profitable and that stock, MHR, is deeply undervalued."

U.S. crude prices have been trading between $80 and $100 lately and with prices now just shy of $98 a barrel, prices won't go much higher, as fuels will rise on oil's coattails and consumers will balk and drive less.

"We don’t see it going to $110 or $120, partly because of supply and demand," Gissen said.

Meanwhile, natural gas looks good as well.

Prices have dropped due to a supply glut, which sent a lot of companies putting production on hold due to profitability concerns.

On the flip side of cheap prices, utilities have used the time to switch from coal to natural gas, while trucking and bus companies have switched over as well.

"We think that will continue, particularly while prices are low. So the low prices of natural gas have encouraged a lot of natural gas consumption. When that consumption continues it will mean that longer term natural gas prices will rise," Gissen said.

"It’s cyclical. They’ll rise to the point where the price gets too high and then consumption will decline. That has not happened so we believe natural gas prices will remain low for about six, nine months. It’s hard to be exact with these projections but longer term natural gas prices should be higher.”

Gold still has room to run as well, though the commodity has steadily gained for over a decade.

Exchange-traded funds (ETF) are a good option for gold, though investors should look at stocks in the companies that mine the metal, the prices of which are lagging behind the metal's past gains.

"The way to play gold right now is probably with ETFs. But longer term there are many gold companies that are deeply undervalued that if investors are patient, they’ll make good money with those investments."